/*
 *
 * Paros and its related class files.
 * 
 * Paros is an HTTP/HTTPS proxy for assessing web application security.
 * Copyright (C) 2003-2004 Chinotec Technologies Company
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the Clarified Artistic License
 * as published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * Clarified Artistic License for more details.
 * 
 * You should have received a copy of the Clarified Artistic License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package org.parosproxy.paros.network;

/**
 * 
 * To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Generation - Code and Comments
 */
public class ByteVector {

	private static final int INITIAL_SIZE = 4096;
	private byte[] buf = null;
	private int bufLen = 0;
	private boolean changed = true;

	public ByteVector() {
		buf = new byte[INITIAL_SIZE];

	}

	public ByteVector(int capacity) {
		buf = new byte[capacity];
	}

	void ensureCapacity(int minimumCapacity) {

		if (buf.length - bufLen >= minimumCapacity) {
			// enough buf, no expand needed.
			return;
		}

		// expand needed

		int expandLength = buf.length * 2;

		if (expandLength - bufLen < minimumCapacity) {
			expandLength = bufLen + minimumCapacity;
		}

		byte[] newBuf = new byte[expandLength];
		System.arraycopy(buf, 0, newBuf, 0, bufLen);
		buf = newBuf;
	}

	public synchronized void append(byte[] b, int offset, int length) {

		ensureCapacity(length);
		System.arraycopy(b, offset, buf, bufLen, length);
		bufLen += length;
		changed = true;
	}

	public void append(byte[] b, int length) {
		append(b, 0, length);

	}

	public void append(byte[] b) {
		append(b, 0, b.length);
	}

	/**
	 * Return the current byte array containing the bytes.
	 * 
	 * @return
	 */
	public byte[] getBytes() {
		if (!changed) {
			return buf;
		}

		byte[] newBuf = new byte[bufLen];
		System.arraycopy(buf, 0, newBuf, 0, bufLen);
		buf = newBuf;
		return buf;
	}

	public int length() {
		return bufLen;
	}

	public void setLength(int length) {

		if (length <= bufLen) {
			bufLen = length;
			return;
		} else {
			byte[] newBuf = new byte[length];
			System.arraycopy(buf, 0, newBuf, 0, bufLen);
			buf = newBuf;
		}

	}
}
